From Toilet to Tiller: Humanure

In the Western Hemisphere, many people might be considered fecophobes. When they go to the bathroom, they want whatever went into the toilet to be whisked away in a hurry. There are folks, however, with a different take. They believe what goes into the toilet should be turned into what's sometimes referred to as humanure. Find out how much you know about the issue in this quiz.

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Question 1 of 20

What percentage of disease outbreaks worldwide are caused by contaminated and polluted water supplies?

20 percent

50 percent

80 percent

The World Health Organization estimates that 80 percent of all disease outbreaks can be tied to poor sanitation and polluted water supplies.

Question 2 of 20

Why is fecal matter and human urine considered a health risk?

It can harbor dangerous pathogens.

Without proper composting, human fecal matter can be home to vast amounts of pathogens -- even if the carrier himself isn’t ill. But while it might smell bad at first, the aroma won’t kill you.

It can produce toxic odors.

Both

Question 3 of 20

By the end of the 20th century, how many septic systems were in use in the United States?

About 5 million

About 20 million

There were about 22 million septic system sites in operation, serving between a quarter to a third of the total population.

About 50 million

Question 4 of 20

Why are many septic systems bad for the environment?

They pollute aquifers.

Septic systems are often major contributors to groundwater pollution, especially when installed near one another in high-density areas. Soil can purify wastewater to a certain extent, but past that, it can lead to dangerous levels of contamination.

They pollute the atmosphere.

Both

Question 5 of 20

What happens to the majority of the sewer sludge that's collected by wastewater treatment plants?

It goes into landfills.

Most of the sewer sludge collected by wastewater treatment plants ends up in landfills, despite the fact that human waste can be composted and potentially used as fertilizer.

It gets burned.

It is turned into fertilizer.

Question 6 of 20

Why isn't all this human waste composted and used for agricultural purposes?

It's mixed with pollutants from other sources.

It's socially taboo to compost human waste.

Both

Most people in the Western world pooh-pooh the notion of repurposing human droppings, but it's also an issue of all the other ingredients -- many of them toxic -- that wind up in the wastewater stream.

Question 7 of 20

Apart from those toxic additives and negative attitudes, what's another concern to keep in mind when discussing the prospect of composting human fecal matter?

The health of the human contributors

Healthier populations tend to host lower levels of dangerous pathogens. Extra care needs to be taken if some members of the populace are more prone to intestinal turmoil.

The time of year the process is set to take place

Both

Question 8 of 20

Using a composting toilet, how much finished compost does the average person produce in a year?

About 60 pounds

About 90 pounds

The average person produces about 90 pounds (about 40 kilograms) of compost each year. It's important to note, though, that a lot more of the initial substance goes into the process. It dries, settles and reduces in mass over time.

About 120 pounds

Question 9 of 20

Using a composting toilet, how much water does the average person spare from contamination in a year?

More than 1,000 gallons

More than 3,000 gallons

More than 6,000 gallons

Talk about some water savings! By using a composting toilet, the average person can prevent more than 6,000 gallons (near 23,000 liters) of clean water from needlessly entering the wastewater stream.

Question 10 of 20

How much bacteria can the urine of a healthy person contain?

Up to 500 bacteria per milliliter

Up to 1,000 bacteria per milliliter

Even healthy people can have bacteria exit their bodies through their urine -- to the tune of up to 1,000 bacteria per milliliter (about a fifth of a teaspoon).

Up to 5,000 bacteria per milliliter

Question 11 of 20

How about someone with a urinary tract infection?

More than 10,000 bacteria per milliliter

More than 50,000 bacteria per milliliter

More than 100,000 bacteria per milliliter

If a person has a urinary tract infection, more than 100,000 bacteria per milliliter (again, only about a fifth of a teaspoon) might be spewing out every time they go to pee.

Question 12 of 20

What transmission route that pathogens take to get to people could theoretically be eliminated if everyone used a composting toilet?

Human to soil to human

When not properly composted, human urine and fecal matter can seep into the soil, providing many pathogens with an environment critical for them to progress their life cycles. If everyone properly composted their waste, in theory these parasites would need to evolve rapidly or face extinction.

Human to animal to human

Both

Question 13 of 20

What temperature must human compost reach to kill roundworm eggs?

52 degrees Fahrenheit (11 degrees Celsius)

94 degrees Fahrenheit (34 degrees Celsius)

101 degrees Fahrenheit (38 degrees Celsius)

To kill roundworm eggs, composting fecal matter must get to at least 101 degrees Fahrenheit. A well-managed composting system can easily surpass that temperature.

Question 14 of 20

How hot must the temperate of a compost pile be to kill all the pathogens it contains in a month?

100 degrees Fahrenheit (38 degrees Celsius)

110 degrees Fahrenheit (43 degrees Celsius)

If you want to ensure all the pathogens are dead, 110 degrees Fahrenheit is a good temperature to aim for.

120 degrees Fahrenheit (50 degrees Celsius)

Question 15 of 20

How hot must the temperature reach to kill all the pathogens in a single day?

114 degrees Fahrenheit (45 degrees Celsius)

117 degrees Fahrenheit (47 degrees Celsius)

122 degrees Fahrenheit (50 degrees Celsius)

Pathogens shouldn't last more than a day if the temperature is maintained at 122 degrees Fahrenheit. It's too far above the cozy familiar 98.6 degrees Fahrenheit they enjoy in their human hosts.

Question 16 of 20

How many compost bins are ideal for composting humanure?

Two

Three

Although you can more if you want, three is a good number of bins. One for filling, one for aging, and one for holding spare organic material needed for cover in both the toilet and the compost pile.

Four

Question 17 of 20

Can kitchen scraps be thrown in the humanure compost pile, too?

Yes

Although you may want to avoid putting kitchen scraps in the composting toilet itself for fear of attracting insects, feel free to add them to the compost bin currently being filled -- they'll help in the decomposition process.

No

It depends

Question 18 of 20

What two elements are most important to the composting process?

Nitrogen and sodium

Sulfur and carbon

Carbon and nitrogen

Carbon and nitrogen, along with oxygen, are the most important elements of the composting process. Nitrogen can be found in human waste (especially urine) and most of the carbon comes from all the carbon-based plant matter added manually to the mix.

Question 19 of 20

Once a composting toilet is full, which part of the active compost pile should receive the remains?

The edges

The center

It's best to keep the top of the compost pile somewhat flattened, and when it's time to make a fresh deposit, put that in a depression in the center of the pile. Then cover it with more of your carbon substrate.

The bottom

Question 20 of 20

But … But aren't composting toilets and the resulting compost piles really stinky?

Yes

No

Only if you're doing it wrong

Composting toilets, and the compost piles that result, shouldn't smell as long as enough carbon-based matter is added. In the toilet, this can be ashes, sawdust, peat moss, or some combination of those and similar substrates. In the compost pile, it can be the same, plus whatever other organic matter you have.